Description
Compute (secondEpoch - firstEpoch) × 2^32 + secondSequence - firstSequence using exact decimal-integer epochs.
TCP sequence and timestamp fields wrap in a 32-bit space. A modular distance gives a local displacement; ordering near half the space and multiple wraps requires additional context.
Compute (secondEpoch - firstEpoch) × 2^32 + secondSequence - firstSequence using exact decimal-integer epochs.
When to use this tool
Use TCP Sequence Epoch Distance when you need a bounded sequence-space distance or interval relationship.
How to use the tool and how it works
- Enter firstEpoch, firstSequence, secondEpoch, secondSequence. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read distanceDecimal. Use the output convention below.
Compute (secondEpoch - firstEpoch) × 2^32 + secondSequence - firstSequence using exact decimal-integer epochs. Return a signed decimal distance.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| firstEpoch | First Epoch | Required. Text; maximum UTF-16 length 8192. Integer syntax: optional + or - and 1-128 decimal digits; leading zeros accepted. Apply the sign restriction above. |
| firstSequence | First Sequence | Required. Safe integer; minimum 0; maximum 4294967295. |
| secondEpoch | Second Epoch | Required. Text; maximum UTF-16 length 8192. Integer syntax: optional + or - and 1-128 decimal digits; leading zeros accepted. Apply the sign restriction above. |
| secondSequence | Second Sequence | Required. Safe integer; minimum 0; maximum 4294967295. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| distanceDecimal | Distance Decimal | Required. Text; maximum UTF-16 length 8192. |
{
"input": {
"firstEpoch": "2",
"firstSequence": 4294967290,
"secondEpoch": "3",
"secondSequence": 4
},
"output": {
"distanceDecimal": "10"
}
}Limitations and assumptions
- Epochs must already be known; this does not discover wrap counts from sequence numbers alone.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Combine sequence arithmetic with connection state, packet chronology, and explicit wrap epochs where available.
References
Similar or alternative tools
- TCP Sequence Halfspace Tie
Calculate the forward distance from first to second modulo 2^32.
- TCP Retransmission Sequence Overlap
Place secondStart within a signed half-space of firstStart, reject the exact half-space tie, and intersect the resulting half-open intervals.